Bispyridyl compounds containing a silicon atom and process of preparation



Patented Mar. 7, 1950 UNITED STATES PATENT OFFICE BISPYRIDYL COMPOUNDSCONTAINING A SILICON ATOM AND PROCESS OF PREP- ARATION Charles F. H.Allen and Donald M. Burness, Rochester, N. Y., assignors to EastmanKodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing.Application June 12, 1948,

7 Serial No. 32,734

compounds in which the linkage between carbon and silicon is interruptedby oxygen, sensitize photographic silver halide emulsions (whetherspectrally sensitized or not) and have the added advantage of notdiffusing appreciably from the emulsions into the film support uponwhich the emulsions are usually coated.

It is, accordingly, an object of our invention to provide a new class ofchemical compounds and a process for preparing them. Another object ofour invention is to provide a new class of chemical compounds which areuseful in increasing the speed and sensitivity of photographic silverhalide emulsions. Still another object is to provide a new class ofchemical compounds useful in increasing the speed and sensitivity ofphotographic silver halide emulsions which do not diffuse from theemulsions into the film support upon which the emulsions are usuallycoated. A still further object is to provide photographic silver halideemulsions (whether spectrally sensitized or not) sensitized with a newclass of chemical compounds, and to a process for preparing suchemulsions. Other objects will become apparent from a consideration ofthe following description.

According to the process of our invention, we prepare our new compoundsbyv interacting an alcohol containing as a substituent, a heterocyclicnucleus of the pyridine series, and an organic dihalosilane. ried out inthe presence of a tertiary organic amine.

The alcohols containing, as a substituent, a heterocyclic nucleus of thepyridine series, which are useful inpracticing our invention, canadvantageously be represented by the general formula:

--zrf on -on)i..= -(on,)..-on wherein Z represents the non-metallicatoms 12 Claims. (01. 260-290) The process is advantageouslycarnecessary to complete a heterocyclic nucleus of the Pyridine series,d represents a positive integer from 1 to 2, and m represents a positiveinteger from 2 to 3. Typical alcohols include, for example, fi-(Z-pyridyl) -ethanol, 7- (2-pyridyl) propanol, 18- (4-methylpyridyl-2)-ethanol, .18- (6- methylpyridyl-2) -ethanol, p-(5-ethylpyridy1-2)ethanol, fl- (4-pyridyl) -ethanol, '7- (4-pyridyl) propanol, fl-(3-ethylpyridyl-4)-ethanol, etc. In addition to containing alkyl substituentssuch as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, etc. (i.e., an allryl group of the formula CnH2n+1 wherein n is a positiveinteger from 1 to 4), the pyridine nucleus can have substituted thereonsuch groups as C1, Br--, ChaO-,

The organic dihalosilanes useful in practicing our invention canadvantageously be represented by the general formula:

X -SPXT wherein R and R1 each represents a member selected from thegroup consisting of an alkyl group, such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, etc. (i. e., an alkyl group of the formulaCnHiln+1 wherein n is a positive integer from 1 to 4) and a mononucleararyl group of the benzene series, e. g., phenyl (CsHs), 0-, mand p-tolyl(CHaCaH4-), o-, mand p-chlorophenyl (C1CsH4-). o-, mand p-bromophenyl(BrC6I-I4), etc. and X1 represents a halogen atom, such as a chlorineatom or a bromine atom.

. Typical silanes include, for example, dibromodimethylsilane,dichlorodimethylsilane, dichlorodiethylsilane,dichlorodi-n-propylsilane, dichlorodiphenylsilane,dibromodiphenylsilane, di-(pbromophenyl) dichlorosilane, dichlorodi(ptclyl) -silane, dichloroethylpropylsilane,dichloroethylisobutylsilane, dichloroethylphenylsilane,dichloro-p-bromophenylphenylsilane, etc.

The process of our invention can advantageously be carried out in thepresence of an organic amine, such as a tertiary organic amine. Typicaltertiary organic amines include, for example, the trialkyl amines, suchas triethyl amine, tri-n-propylamine, trilsopropylamine,trl-nbutylamine, triisobutylamine, the tertiary aromatic amines, such asN,N-dimethylaniline, N,N- diethylaniline, N,N-dipropylaniline, etc., andthe tertiary heterocyclic amines, such as pyridine,

quinoline, isoquinoline, a-picoline, p-picoline,

2,500,110 4 be carried out in a solvent which does not react the aboveformula represents a bromide ion or an with any of the materials presentin the .rciodide ion can convenientlybe prepared by interaction mixture.Typical solvents include the diacting a quaternary salt of ourbis-pyridyl comaikyl ethers, such as diethyl ether, diisopropyl pounds,suchasthe d-methyl-p-toluenesulionate, ether, etc., the halogenatedhydrocarbons, such 5 with potassium bromide and potassium iodide,reaschloroform, carbon tetrachloride, ethylene dispectively. Compounds whereX represents a chloride, etc., 1,4-dioxane, the normally liquidperchlorate '(ClOr) ion can advantageously be hydrocarbons, such asn-heptane, benzene, prepared by interacting a quaternary salt of ourtoluene, o-, mand p-xylenes, etc. The tembls-pyridyl compounds, such asthe dimetho-pperature at which our process can be carried outtcluenesulfonate, with sodium perchlorate. Comvaries and is generally afunction of the repounds where Xrepresents a chloride ion or athiactants emp oye W av found that ocyano (SCN-) ion can conveniently beobtained peratures of from to 40 C. are usually suillby interacting aquaternary salt where X reprecien f r h rp 0! r inve n, h h sents aniodide ion with a methanol suspension of lower or higher temperaturescan be used, if de- 15 silver chloride or silver thiocyanate,respectively. sired. Other methods of preparing our new quaternaryammonium compounds can be used, if desired, The process or our inventioncan conveniently Such methods are commonly employed and are beillustrated by the following general equation: well known to thoseskilled in the art. For exa -z sf-icn- -cn)-,==ccm).-0-%l-ocm)..-C"===oa-on le R1 wherein R, R1- Z, d and m have definitions desigample,compounds where X represents a halide nated above. The hydrogen halideHXi which is ion can be prepared by heating our new free bases formedduring the reaction readily combines with with the appropriate alkylhalide in a sealed tube.

the tertiary organic amine to form a salt which The following exampleswill serve to illustrate can be filtered oil from the reaction mixture.further the manner whereby we practice our in- Our new bis-pyridylcompounds, which are obvention.

tained as free bases in the reaction illustrated above, can be furthertreated to obtain their qua- Example WOW] ternary salts. For example,when the free base is heated with an alkyl ester of p-toluenesulfonicacid, a quaternary ammonium compound is readily formed. Other quaternaryammonium can compounds can be readily prepared by heating 40 the freebases with a compound containing an acidic anion. Another method forpreparing q a y ammonium compounds of our new 35.1 parts by weight of7-(2-pyrldyl)-propanol bases comprises heating one of the alkyl sulfuric(B. P. 134 to 139 C./11 mm.) were dissolved in or sulfonic acid esteraddition salts of our new 250 parts by weight of anhydrous diethylether, bases with an inorganic salt (1. e., by double deand 30 parts byweight of triethylamine added.

composition). The quaternary addition com- While this solution wasvigorously stirred, a secpounds which are readily obtainable from our0nd solution of 20 parts by weight of redistilled new bases can berepresented by the general fortechnical dichlorodiethylsiiane inanhydrous dimula: ethyl ether was added dropwise. After the addia z fl zRI I-1 :(CH--CH) =;b-(CHQ-OBlo-(CHI)||6= ZCH*CH)d-l wherein R, R1, Z, dand m have the definitions destion was complete, the mixture was stirredfor an ignated above, and R2 represents an alkyl group. additional hourat room temperature (20-25 C.) such as methyl, ethyl, n-propyl,isopropyl, n-butyl, and then filtered. The ethereal filtrate wasisobutyl, sec-n-butyl, amyl, etc. (i. e., an alkyl washed thoroughlywith water, dried, and alter group of the formula Cam's-+1 wherein nrepreremoval of the ether, the residue was fractionally sents a positiveinteger from 1 to 5), and X repdistilled under a vacuum. There were thusobresents an anion (or acid radical), such as halide tained 33 parts byweight of dlethyl-di-[y-(Z- (e. g., C1-, Br-, 1-), perchlorate 0104-),thiopyridyD-propoxy] silane distilling at 194 to 198' cyano (SCN'),alkylsulfate (e. g., CHJSOA"), ben- C./1.5 mm. The analysis of thiscompound zenesulfonate (Cal-158020), p-toluenesulfonate 05 was asfollows:

(p-CHaCeH4SO2O-), etc. Typical esters which can be reacted directly byheating with our new bases to ive useful quaternary salts includediemulated Found methylsulfate, diethylsulfate, methylbenzenesul- C 67 06m fonate, ethyl benzenesulfonate, n-propyl benzene- 70 a. s14 assulfonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, n-propylp-toluenesulfonate, n-butyl p-toluenesulfonate, isobutylp-toluenesulfowhen an ethereal solution of 0.256 mol of hate,sec-n-butyl p-toluenesulfonate, n-amyl p- 7-(4-pyridyl)-propano1 wasreacted with an toluenesulfonate, etc. Compounds wherein X in 76ethereal solution of 0.127 mol of dichlorodiethylsilane in the presenceor trlethylamine in exactly the same manner as described in Example I,diethyLdi-[y- (4-pyridyl) -propoxyl silane boiling at 210 to 216 C./1.5mm. was obtained. The

formula of this compound can berepresented as:

- 01H: CHrCHrCHt-O-AiOCKr-CHt-CH The analysis of this compound was asfollows:

Calculated Found Example Il.Diethyl-di- [p- (Z-pyridul) -etho:ul

silane filtrate was washed thoroughly with water, dried and, afterdistilling off the ether from the solution, the residue was fractionallydistilled. There were thus obtained 28.6 parts by weight ofdiethyl-di-[p-(2-pyridyl)-ethoxy] silane as a pale yellow liquiddistilling at 158 to 162 C./1 mm. The analysis of this compound gave thefollowing results:

Calculated Found When an ethereal solution of 0.256 mol of B-(l-pyridyl)-ethanol was reacted with an ethereal solution of 0.127 mol ofdichlorodiethylsilane in the presence of triethylamine in exactly thesame manner as described in Example II, diethyldi-ifi-(i-pyridyl)-ethoxy] silane distilling at 199 to 204 C./3mm-. was obtained. Theformula of this compound can be represented as:

j can VCHr-CIIrO-A The analysis of this compound gave the followingresults:

CHx-C HrCHz-O- Si-O-CHrC HrCH Calculated Found When an ethereal solutionof 0.256 mol of p- (5- ethylpyridyl-2) -ethanol is reacted with anethereal solution or 0.127 mol of dibromodimethylsilane in the presenceof quinoline in exactly the same manner as described in ExampleIIJdi-[p- (5-ethylpyridyl-2-ethoxyl dimethylsilane represented by theformula;

can be obtained. In like manner, when an ethereal solution of 0.256 molof ,8-(3-ethylpyridyl-4)-ethanol is reacted with an ethereal solution of0.127 mol of dichloroethylisobutylsilane in the presence ordimethylaniline, di te- (3-ethylpyridyl-4)-ethoxy] ethylisobutylsilanerepresented by the formula:

CrHi

can be obtained.

Example III.Dieth1 Z di ['y -(2 pyridyD- propoxz l silane dimetho-ptoluenesulfonate CQHI I N .2 p-CliiaCoHrS 0:0-

4.8 parts by weight of methyl p-toluenesulfonate were added to 3.6 partsby weight of the diethyl-di-[Y-(2-pyridyl) -propoxy] silane obtained inExample I, and the mixture was heated at to C. on an oil bath for onehour.. The excess methyl p-toluenesulfonate which was used was removedby extraction with warm benzene, all traces of which were removed underreduced pressure. A quantitative yield (7.3 parts by weight) ofdiethyl-di-[7-(2-pyridyl) -propoxy] silane dimetho-p-toluenesulfonatewas obtained.

It was found to be soluble in water, ethyl alcohol or hot acetone, butinsoluble in hydrocarbon solvents, such as benzene, etc.

When 4.8 parts by weight of methyl p-toluenesulfonate were added to 3.6parts by weight of the diethyl-di-[y-(i-pyridyl) -propoxy] silaneobtained in Example I, dieth'yl-di-[y-(-pyridyl)- propoxy] silanedimetho-p-t0luenesulfonate, which exhibited solubility propertiessimilar to those of the product obtained in Example III, was obtained.When either of these dimetho-ptoluenesulfonates are warmed with amethanol solution of potassium iodide, the corresponding dimeth iodidesare readily formed. When these dimeth iodides are warmed with a methanolsolution of silver thiocyanate (Ag SCN), the

corresponding dimetho thiocyanates are formed with ease.

Example IV.-Diethyl-di-[fi-(Z-pvridyl)ethorill silanedimetho-p-toluenesulfonate 4.8 parts by weight of methylp-toluenesuiiohate were added to 3.3 parts by weight of the diethyldi-{3- (Z-pyridyl) -ethoxyl silane obtained in Example II, and the mixturewas heated on a steam bath for one hour. The excess methylp-toluenesulfonate which was used was removed by extraction with warmbenzene, all traces of which were removed by warming the residue under avacuum. An almost quantitative yield (6.5 parts by weight) ofdiethyl-di- [/3- (Z-pyridyl) ethoxy] silane dimetho p-toluenesulfonatewas thus obtained. It was found to be soluble in water, ethyl alcohol orwarm acetone, but insoluble in hydrocarbon solvents, such as benzene.

When 4.8 parts by weight of methyl p-toluenesulionate were added to 3.3parts by weight of diethyl-di-[fi-Ol pyridyl) ethoxy] silane obtained inExample II, and the mixture warmed on a steam bath for one hour,diethyl-di-[p- (4-pyridyD-ethoxy] silane dimetho p-toluenesulfonate,which exhibited solubility properties similar to those of the productsobtained in Examples III and IV, was obtained. When either of thesedimetho p-toluenesulfonates are warmed with a methanol solution ofsodium perchlorate, the corresponding dimetho perchlorates are readilyformed.

Similarly, when 0.01 mol of di-[B-(3-ethylpyridyi-4)-ethoxy]ethylisobutylsilane is warmed with 0.0275 mol of diethylsulfate, and theexcess diethylsulfate removed as described above, di-[fi-(B-ethylpyridyl 4) ethoxy] ethylisobutylsilane diethyl sulfaterepresented by the formula:

can be obtained.

Example V.-Diphenyl-di- [{3- (Z-pyridyl-ethoxy] silane 31.5 parts byweight of [3-(2-pyridy1) -ethanol were dissolved in 250 parts by weightof anhydrous diethyl ether, and parts by weight of triethylamine added.While this solution was vigorously stirred, a second solution of 32.1parts by weight of redistilled technical dichiorodiphenyisilane inanhydrous diethyl ether was added dropwise. After the addition wascomplete, the mixture was stirred for an additional hour at roomtemperature (20-25 C.) and then filtered. The ethereal filtrate waswashed thoroughly with water, dried, and after removal of the ether, theresidue was iractionaliy distilled under a vacuum. There was thusobtained, dlphenyl-di-[fi-(2-pyridyl) -ethoxyl 51- lane as a yellow oildistilling at 221 C./1 mm. This oil darkened on standing.

When a molecularly equivalent amount of dichlorodi-(p-tolyi) silane isreacted with 542- pyridyl) -ethanol in accordance with the processdescribed above, di-[fl-(Z-pyridyD-ethoxyl di- (p-tolyl) silanerepresented by the formula:

is formed.

Example VI.Diphem/l-di- [p-(Z-puridyl) ethomy] silanedimetho-p-toluenesulfonate 4.8 parts by weight 0! methylp-toluenesulfonate were added to 4.3 parts by weight of the diphenyl-di-B- (Z-pyridyl) -ethoxy] silane obtained in Example V, and the mixturewas heated on a steam bath at IOU- C. for one hour. The excess methylp-toluenesulionaie was removed by dissolvin the reaction mixture inwater and extracting with benzene. The last traces of methylp-toluenesultonate were removed by warming the aqueous solution in avacuum, and the water was then removed under reduced pressure. Thereremained an almost quantitative yield of diphenyl-di-[fi-(Z-pyridyD-ethoxy] silane dimetho-p-toluenesulfonate as an amber oil. Itwas soluble in water, alcohol, and acetone, but insoluble in benzene.When this dimetho-p-toluenesultonate is reacted with a methanol solutionof potassium bromide, the quaternary salt, diphenyl-di-[,B-(Z-pyridyl)-ethoxy] silane dimethobromide is readily formed. Similarly, by reactingthis dimetho-p-toluenesulfonate with a methanol solution of potassiumiodide, diphenyl-di- [,3- (Z-pyridyl) -ethoxy] silane dimethiodide isformed.

Operating in a similar manner, other bis -or methyl alcohol.

pyridyl compounds, as well as their quaternary ammonium salts, can beprepared by reacting alkanols substituted by a pyridyl nucleus withother organic dihalogenosilanes in the presence of a tertiary organicamine. For example, when fi-(4-methylpyridyl-2)-ethanol is reacted withdichlorodipropylsilane in the presence of triethylamine, di- [,8-(4-methylpyridyl-2) -ethoxyl dipropylsilane represented by the formula:

can be obtained. when propyl benzenesulfonate is warmed with this base,the dipropo benzenesulfonate addition salt is readily formed.

In accordance with our invention, the polyammonium salts of ourbis-pyridyl compounds can be incorporated in photographic silver halideemulsions in any suitable form, e. g., .in the form of a solution in asuitable solvent, such as water The olyammonium salts should bethoroughly incorporated in the emulsion. Since the introduction ofhalide anions into photographic silver halide emulsions alters thehalide concentration in the emulsion, and compensating changes in theemulsion may be desirable, if such poly-ammonium salts are employed, wegenerally prefer to employ polyammonium salts containing anions otherthan halides. Perchlorates and p-toluenesulfonates have been found to beespecially useful.

In the case of spectrally sensitized emulsions,

the polyammonium salts of our bis-pyridyl compounds can be incorporatedin the emulsion before, simultaneously with or afterthe sensitizing dye,although in some cases it may be advantageous to incorporate thesensitizing dye before incorporating the polyammonium salt. The methodsof incorporating sensitizing dyes in emulsions are, of course, wellknown to those skilled in the art. Ordinarily, it is advantageous toemploy a solution of the sensitizing dye in a suitable solvent, e. g.,methyl alcohol; ethyl alcohol or acetone can be employed in cases wherethe solubility of the sensitizing dye in methyl alcohol is very low.Sensitizing dyes are ordinarily incorporated in the washed, finishedemulsions, and, in accordance with our invention, the polyammonium saltsare advantageously also incorporated in the washed, finished emulsions.However, the polyammonium salts can be added to the emulsion during thepreparation thereof, i. e., during the precipitation, the firstdigestion or the second digestion (ripening). After preparing theemulsions in the presence of the polyammonium salts, the sensitizingdyes can be incorporated in the so-prepared emulsions.

The quantity of the polyammonium salt which is most advantageouslyemployed varies with the nature of the polyammonium salt and with thenature of the emulsion. In most instances,

a satisfactory concentration was found to be between about 20 mg. and200 mg. of th polyammonium salt per gram-mole of silver halide in theemulsion, although greater or smaller concentrations could be employed.We have found, however, that too large quantities of the polyammoniumsalts are advantageously avoided, since excesses tend to produce foginthe emulsions.

Th upper range of concentration for any particular one of ourpolyammonium salts in any particular type of emulsioncan be determinedby employing a series of concentrations of the polyammonium saltseparately in several batches of the same emulsion, and determining thesensitivity of the several emulsions before and'after incorporation ofour polyammonium salt or salts. This method of determining the optimumconcentration may be carried out in any conventional manner. Briefly,the method we would employ would comprise coating the aforementionedemulsions in suitable thickness onto glass plates and then testing theresultant photos graphic plates in a wedge spectograph and asensitometer, whereby the spectral sensitivity and speed of the emulsionon th plate may be determined.

When employing spectrally sensitized emulsions, the spectral sensitizersare advantageously employed in about their optimum concentration, which,for most purposes may be considered as lying between about 3 mg. and 20mg, of spectral sensitizer per liter of emulsion containing about 0.25mole of silver halide, although it is to be understood that these valuesare merely set forth for purposes 0! illustration and the concentrationsabove or below the aforementioned concentrations can be employed. Withfine-grain emulsions (which includes many of the ordinarily employedsilver chloride emulsions), the ratio of the sensitizing dye to theconcentration of the silver halide in the emulsion may advantageously belarger than in the coarser-grained emulsions, where smaller amounts ofsensitizing dye will, in many instances, give satisfactory or optimumsensitization. The optimum concentration, as discussed herein, of asensitizing dye, namely the concentration at which the apparentlygreater sensitivity occurs, can also be determined in any conventionalmanner known to those skilled in the art by measuring the sensitivity ofa series of emulsions containing different concentrations of thesensitizing material.

We wish to point out, however, that when our polyammonium salts areincorporated into a spectrally sensitizedemuision (as contrasted to anunsensitized emulsion), it is desirable that the sensitizing dye becompatible with our polyammonium salt.

For this reason, as spectral sensitizers (sensitizing dyes), we wouldemploy only those which are substantially non-acidic. As non-acidicsensitizing dyes, we include all the known neutral and basic sensitizingdyes, and it is to be understood that our invention is not restricted inthis respect. Examples of some of the non-acidic sensitizing dyes arethe sensitizing cyanine dyes (see, for example. United States Patents 1846,300; 1,846,301; 1,846,302; 1,846,303 and 1,846,304, each datedFebruary 28, 1932; United States Patent 1,861,836, dated June 7, 1932;United States Patent 1,939,201, dated December 12, 1933; United StatesPatent 1,942,854, dated January 9, 1934; United States Patent 1,957,869,dated May 8, 1934; United States Patent 1,962,124, dated June 12, 1934;United States Patent 1,969,446, dated August 7, 1934; United StatesPatent 1,973,462, dated September 11, 1934 United States Patent1,990,507, dated February 12, 1935; United States Patent 2,094,580,dated October 5, 1937; United States Patent 2,112,140, dated March 22,1938, and French Patent 757,813, published January 5, 1934), thesensitizing merocyanine ,dyes (see United States Patent 2,078,233, datedApril 27, 1937; United States Patent 2,089,729, dated August 10, 1937;United States Patent 2,153,169, whereinRand R1 each represents an alkylgroup dated April 4, 1939; and United ,States Patents of the formulaCnHZn-H wherein n is a positive 2,177,401, 2,177,402, and 2,177,403,dated October integer from 1 to 4.

1939), the sensitizing ya ine dyes see 4. A bis-pyridyl compoundselected from those United States Patent 2,166,736, dated July 18,represented by the general formula;

1939) and the sensitizing hemioxonol dyes (see United States Patent2,165,339, dated July 11,

1939, and French Patent 841,632, published May f 24, 1939). N/ H:)- lHi)-- \N It is consequently apparent from the foregoing l0 n, that ourpolyammonium salts may be incorpo- X x R: J rated in emulsionscontaining a large variety of wherein R and R1 each represents an alkylgroup diflerent sensitizing dyes. of the formula CnHZn-H. wherein n is apositive S already Pointed out, 1 p o ess s subject integer from 1 to 4,R2 represents an alkyl group to considerable variation, particularly asrespects of the formula CnHin-l-l wherein n is a positive the method ofaddition of our polyammonium integer from 1 to 5, mrepresents a positiveinteger salts, the type of photographic material treated from 2 to 3 andX represents an anion. (spectrally sensitized or not) and the nature of5. A bis-pyridyl compound selected from those the material and amountsadded. Our invention represented by the general formula: is useful forall types of optically sensitized emulsions, especially unsensitizedemulsions of R relatively low iodide content. 1

What we claim and desire secured by Letters r 0-GH,-CH, \N Patent of theUnited States is: v R

1. A bis-pyridyl compound selected from those RI X X n: represented bythe two general formulas: wherein R and R1 each represents an kyl gr upz R ,,.z N1:-(-CH-- mai iboHnr-o-si-mom).-6 on flh-lfq and R! z II R,

ti' lcfl cmd-i bom)..-o-si -oonl)rdwln-cmi-i" x 1 \X wherein Zrepresents the non-metallic atoms of the formula CnHZvH-l wherein n is apositive necessary to complete a heterocyclic nucleus of int r from 1 to4. R2 repres ts an a yl up the pyridine series, R and R1 each represents3, 0f the formula CnHZrH-l wherein Tl 1S 8. positive member selectedfrom the group consisting of an 40 integer from t0 and X represents ananion.

alkyl group of the formula CnH2n+1 wherein n A bis-pyridyl compoundrepresented by the is a positive integer from 1 to 4, and a monoformula:nuclear aryl group of the benzene series, R2 represents an alkyl groupof the formula CnH27i+1 I wherein n is a positive integer from 1 to 5, mrepresents a positive integer from 2 to 3, d rep- N/ CHFCHFO QX OCH' CHa resents a positive integer from 1 to 2, and X rep- 1 resents an anion.7. A bis-pyridyl compound represented by the 2. A bis-pyridyl compoundselected from those a! represented by the general formula:

C311 6 g N/ om-cHr-oHr-og-o-om-oHr-OH= CHrCHg-0--Bl0CH2-CH: :m N 1 N 8.A bis-pyridyl compound represented by the formula:

01H! Ii-I CHr-CH:-()Ai-;IOCH:CHr fi -2p=CBiClH|SO:O' (13H; 2 (EH1wherein R and R1 each represents an alkyl group of the formula CnH2n+1wherein n is a positive integer from 1 to 4.

9. A process for preparing a bis-pyridyl compound selected from thoserepresented by the general formula:

n z z l= on--oml ,=oom),..-o-sl -oon, .,-6= on-orl)l ,==N

3. A bis-pyridyl compound selected from those wherein Z represents thenon-metallic atoms represented by the general formula: necessary tocomplete a heterocyclic nucleus of the pyridine series,'R and R1 eachrepresents a R member selected from the group consisting of an all: 1rou of the N, CHECHPCHPO QI O CH, CHPCHP\ y g p formula CnH2n+i whereinn is a positive integer from 1 to 4 and a mononuclear i aryl group ofthe benzene series, d represents a positive integer from 1 to 2, and mrepresents a positive integer from 2 to 3, comprising reacting acompound selected from thou represented by the general formula:

R Xr-Al-Xl wherein R and R1 each represents a member selected from thegroup consisting of an alkyl group of the formula Cums-+1 wherein n is apositive integer from 1 to 4 and a mononuclear aryl group of the benzeneseries and Xi represents a halogen atom in the presence of a tertiaryorganic amine.

10. A process for preparing a bis-pyridyl compound selected from thoserepresented by the general formula:

wherein R and R1 each represents an alkyl group of the formula CnHmH-iwherein n is a positive integer from 1 to 4 and m is a positive integerfrom 2 to 3, comprising reacting a compound selected from thoserepresented by the general formula:

(CHQrOH wherein m represents a positive integer from 2 to 3, with asilaneselected from those represented by the formula:

wherein R and R1 each represents an alkyl group of the formula CnH2n+1wherein n is a positive integer from 1 to 4 and X1 represents a halogenatom in the presence of a tertiary organic amine.

11. A process for preparing a bis-pyridyl com.- pound selected fromthose represented by the general formula:

wherein R. and R1 each represents an alkyl group of the formula CnH2n+1wherein n is a positive integer from 1 to 4 and m is a positive integerfrom 2 to 3, comprising reacting a compound selected from thoserepresented by the general formula:

wherein m represents a positive integer from 2 to 3, with a silaneselected from those represented by the formula:

wherein R and R1 each represents an alkyl group of the formula CnH2n+1wherein n is a positive integer from 1 to 4, in the presence of atrialkyl amine.

12. A process for preparing a bis-pyridyl compound selected from thoserepresented by the general formula:

wherein R and R1 each represents an alkyl group of the formula CnH2n+iwherein n is a positive integer from 1 to 4 and m is a positive integerfrom 2 to 3, comprising reacting a compound selected from thoserepresented by the general formula:

I cunt-mu wherein m represents a positive integer from 2 to 3, with asilane represented by the formula:

in the presence of a trialkyl amine.

CHARLES F. H. ALLEN. DONALD M. BURNESS.

No references cited.

Certificate of Correction 1 Patent No. 2,500,110 March 7, 1950 CHARLESF. H. ALLEN ET AL.

It is hereby certified that errors appear in the printed specificationof the above numbered patent requiring correction as follows:

Column 6, line 12, for -2-ethoxy] read -2) ethoxy] Example III, for thatportion of the formula reading column 7, Example IV, second formulathereof, for that portion reading Ha Ha Example V, in the formula, forCH GH, read 0H,--OH,; column 8, lines 38 to 40, inclusive, for

column 12, line 60, for that portion of the formula reading .2p==CH;read .2p-C'H,

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the casein the PatentOffice.

Signed and sealed this 4th day of July, A. I). 1950.

THOMAS F. MURPHY,

Assistant C'omrm'aaioner of Patents.

1. A BIS-PYRIDYL COMPOUND SELECTED FROM THOSE REPRESENTED BY THE TWOGENERAL FORMULAS: